The present invention relates in general to display devices and more particularly to an edge emitting organic light emitting diode.
Conventional displays are large, heavy, expensive, and require a relatively large amount of electrical power, especially portable computer displays. Several different types of displays exist, including passive matrixed addressed displays and conventional organic light emitting diode displays. The different types of displays have various disadvantages that may affect the performance of the display.
Passive matrixed addressed displays suffer from crosstalk or spurious outputs from unaddressed pixels due to leakage current flow in reversed biased unaddressed pixels. Further, as the number of rows increases, very short duty cycles are required. Duty cycle is inversely proportional to the number of rows of the display and thus the peak current density and peak luminance increases with the number of rows. Each pixel in a 1000 row display has a duty cycle of 0.1%. The peak current density during bias is 1000 times the DC level required for the same average luminance. Such a situation leads to reliability problems in the display.
For conventional organic light emitting diodes, it is difficult to fabricate full color displays due to the patterning required for the various color organic semiconductors. Further, sensitivity of the organic semiconductors makes patterning above them a difficult task. Added expense is incurred in order to attach driver circuits to the display. Therefore, it is desirable to provide a more reliable and cost effective display.
From the foregoing, it may be appreciated that a need has arisen for an edge emitting display device that is more reliable and less difficult to fabricate than conventional display devices. In accordance with the present invention, an edge emitting organic light emitting diode is provided that substantially eliminates or reduces disadvantages and problems of conventional display devices.
According to an embodiment of the present invention, there is provided an edge emitting organic light emitting diode that includes a substrate layer with display drivers incorporated therein. A first emitter array is formed above the substrate layer. A second emitter array is formed above the first emitter array. A third emitter array is formed above the second emitter array. The first, second, and third emitter arrays provide the colors red, green, and blue for a plurality of pixels associated with each emitter array.
The present invention provides various technical advantages over conventional display devices. For example, one technical advantage is in having organic semiconductor color layers formed over a substrate that incorporates display drivers for each color layer. Another technical advantage is in fabricating a display device without patterning the various organic semiconductor color layers or patterning a metal layer above the color layers. Yet another technical advantage is in eliminating crosstalk among pixels. Still another technical advantage is in reducing the peak currents needed to operate the display device, thus improving reliability. Other technical advantages may be readily apparent to those skilled in the art from the following figures, description, and claims.